Which wall construction specification outlines the requirements for exterior window and door installations?

The correct answer is Wall Construction R609 because this section specifically addresses the requirements and standards for the installation of exterior windows and doors. It outlines the necessary protocols to ensure that these openings are securely fitted, properly flashed, and insulated, thereby contributing to the overall energy efficiency and structural integrity of the building. Proper installation as specified in R609 helps to prevent issues such as air and water infiltration, which can lead to a variety of problems including mold, rot, and energy loss.

Other sections, while dealing with general wall construction standards, do not focus specifically on exterior openings like windows and doors, making R609 the most relevant and comprehensive for these particular installations.